Display device

ABSTRACT

A display device including: a plurality of drive electrodes extending in a first direction and arranged side-by-side in a second direction with an inter-electrode slit in between; and a plurality of pixel electrodes arranged in matrix in the first and second directions. Each of the drive electrodes has one or more inner-electrode slits, and a center of the pixel electrode is located in the inter-electrode slit or in the inner-electrode slit.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.14/322,329 filed Jul. 2, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/211,477 filed Aug. 17, 2011, now U.S. Pat. No.8,803,858 issued Aug. 12, 2014, the entireties of which are incorporatedherein by reference to the extent permitted by law. The presentapplication claims the benefit of priority to Japanese PatentApplication No. JP 2010-187176 filed on Aug. 24, 2010 in the JapanPatent Office, the entirety of which is incorporated by reference hereinto the extent permitted by law.

BACKGROUND

This disclosure relates to a display device suitable for a liquidcrystal display of a vertical alignment (VA) mode, especially of amulti-domain vertical alignment (MVA) mode.

A liquid crystal display of a vertical alignment (VA) mode, whichutilizes vertical alignment type liquid crystals, has been used inrecent years. For example, Japanese Unexamined Patent ApplicationPublication No. 2008-129193 discloses a liquid crystal display of the VAmode having a configuration in which pixel electrodes and driveelectrodes (common electrodes) are disposed to oppose each other withthe VA liquid crystals in between, and slits are provided for both thepixel electrodes and the drive electrodes. In both of the pixelelectrodes and the drive electrodes, the slits are provided in pixelunit. The slits provided in the drive electrodes are formed in adiscontinuous fashion in a horizontal direction within a plane, and donot extend in the horizontal direction within the plane, for example.

SUMMARY

A configuration of drive electrodes may be contemplated which utilizesthe plurality of drive electrodes that extend in a horizontal directionand that are divided in a vertical direction. However, a slit-likeclearance is generated in the horizontal direction between the adjacentdrive electrodes in the configuration which utilizes the plurality ofdrive electrodes that are divided as described above. Thus, states oforientation of liquid crystal molecules are disturbed due to astructural difference between a portion where the slit-like clearance isformed and a portion where the drive electrode is formed. As a result, aportion corresponding to the slit-like clearance may be seen as astreak-like display defect.

It is desirable to provide a display device capable of performing anefficient orientation control which is suitable for a liquid crystaldisplay of a VA mode, and capable of suppressing deterioration indisplay quality in the VA mode liquid crystal display.

A display device according to an embodiment of the technology includes:a plurality of drive electrodes extending, in a first direction, with alength larger than that of an effective display region, and arrangedside-by-side in a second direction with an inter-electrode slit inbetween, each of the drive electrodes being supplied with a drivesignal; and a plurality of pixel electrodes arranged in matrix in thefirst and second directions to face the drive electrodes, each of thepixel electrodes being supplied with an image signal. Theinter-electrode slit extends to pass through a center region of each ofthe pixel electrodes.

A display device according to another embodiment of the technologyincludes: a plurality of drive electrodes extending in a first directionand arranged side-by-side in a second direction with an inter-electrodeslit in between; and a plurality of pixel electrodes arranged in matrixin the first and second directions. Each of the drive electrodes has oneor more inner-electrode slits, and a center of the pixel electrode islocated in the inter-electrode slit or in the inner-electrode slit.

In the display devices according to the embodiments of the technology,the inter-electrode slit extends to pass through the center region ofeach of the pixel electrodes (the center of the pixel electrode islocated in the inter-electrode slit or in the inner-electrode slit).Thus, an efficient orientation control suitable for a liquid crystaldisplay of a vertical alignment mode is possible, as compared with anexample where a slit is disposed between the adjacent pixel electrodes.

Advantageously, each of the drive electrodes has a width in the seconddirection corresponding to a size in the second direction of the two ormore pixel electrodes, and has one or more inner-electrode slitsextending in the first direction at least within the effective displayregion, and each of the inner-electrode slit and the inter-electrodeslit extends to pass through center regions of pixel electrodes whichbelong to a pixel line in the first direction.

In this embodiment, each of the drive electrodes has the one or moreinner-electrode slits extending in the first direction at least withinthe effective display region, and the inter-electrode slit correspondingto the inner-electrode slit is formed between the two adjacent driveelectrodes. Thus, a structural difference between a portion where thedrive electrode is formed and a portion between the two adjacent driveelectrodes is reduced.

According to the display devices of the embodiments of the technology,each of the inner-electrode slit and the inter-electrode slit extends topass through center regions of pixel electrodes. Hence, it is possibleto perform an efficient orientation control suitable for the VA modeliquid crystal display, as compared with an example where a slit isdisposed between the adjacent pixel electrodes.

Also, each of the drive electrodes has the one or more inner-electrodeslits extending in the first direction at least within the effectivedisplay region, in the embodiment where each of the drive electrodes hasa width in the second direction corresponding to a size in the seconddirection of the two or more pixel electrodes. This makes it possible toreduce a structural difference between a portion where the driveelectrode is formed and a portion between the two adjacent driveelectrodes. Thus, it is possible to uniformize states of orientation ofliquid crystal molecules throughout the entire display region when thedisplay device is applied to the liquid crystal display of the VA mode.Hence, it is possible to suppress deterioration in display quality inthe VA mode liquid crystal display.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of thetechnology.

FIG. 1 is a cross-sectional view illustrating an exemplary configurationof a display device according to a first embodiment of the technology.

FIG. 2 is a block diagram illustrating an exemplary configuration of adrive circuit in the display device illustrated in FIG. 1.

FIG. 3 is a plan view illustrating an exemplary configuration of driveelectrodes in the display device illustrated in FIG. 1.

Part (A) of FIG. 4 is a plan view illustrating a connection structure ofthe drive electrodes and a pixel substrate in the display deviceillustrated in FIG. 1, and part (B) of FIG. 4 is a cross-sectional viewillustrating a relevant part of a connection portion of the driveelectrode and the pixel substrate.

FIG. 5 is a plan view illustrating an example of a correspondencerelationship between the drive electrodes and pixel electrodes in thedisplay device illustrated in FIG. 1.

FIG. 6 is a perspective view illustrating the exemplary configuration ofthe drive electrodes in the display device illustrated in FIG. 1.

FIG. 7A is a cross-sectional view of a relevant part illustratingorientation states of liquid crystal molecules in a state when there isno potential difference between the pixel electrodes and the driveelectrodes in the display device illustrated in FIG. 1, and FIG. 7B is across-sectional view of the relevant part illustrating the orientationstates of the liquid crystal molecules in a state when there is apotential difference between the pixel electrodes and the driveelectrodes in the display device illustrated in FIG. 1.

FIG. 8 is a cross-sectional view of a relevant part illustrating anexample of lines of electric force between the pixel electrodes and thedrive electrodes generated in the state illustrated in FIG. 7B.

FIG. 9 is a characteristic diagram illustrating a human luminosityfactor.

FIG. 10 is a plan view illustrating a specific design example of thedrive electrodes in the display device illustrated in FIG. 1.

FIG. 11 describes a measurement environment of a specific example.

FIG. 12 describes a result of measurement on recognition of a slit whena pitch of the slit of a drive electrode is varied in the display deviceillustrated in FIG. 1.

FIG. 13 is a plan view for describing a timing of applying signalsbetween the drive electrodes and the pixel electrodes.

FIG. 14 is a timing chart in which (A) and (B) each illustrate a drivingtiming of the drive electrodes in the configuration illustrated in FIG.13, and (C) to (E) each illustrate a scanning timing of the pixelelectrodes.

FIG. 15 is a plan view illustrating a configuration of drive electrodesin a display device according to a second embodiment of the technology.

FIG. 16 is a timing chart in which (A) to (C) each illustrate a drivingtiming of the drive electrodes in the configuration illustrated in FIG.15, and (D) and (E) each illustrate a scanning timing of the pixelelectrodes.

FIG. 17 is a plan view illustrating a configuration of drive electrodesin a display device according to a third embodiment of the technology.

FIG. 18 is a plan view illustrating a configuration of drive electrodesin a display device according to a fourth embodiment of the technology.

FIG. 19 is a plan view illustrating a configuration in sub-pixel unit ofthe drive electrodes and pixel electrodes in the display deviceaccording to the fourth embodiment.

FIG. 20 is an enlarged plan view illustrating a relevant part of thedrive electrodes and of the pixel electrodes illustrated in FIG. 19.

FIG. 21 is a plan view illustrating a configuration of drive electrodesand pixel electrodes in a display device according to a fifth embodimentof the technology.

FIG. 22 is an enlarged plan view illustrating a relevant part of thedrive electrodes and of the pixel electrodes illustrated in FIG. 21.

FIG. 23 is a plan view illustrating an exemplary configuration of driveelectrodes in a display device according to a comparative example.

FIG. 24A is a cross-sectional view of a relevant part illustratingorientation states of liquid crystal molecules in a state when there isno potential difference between pixel electrodes and the driveelectrodes in the configuration according to the comparative exampleillustrated in FIG. 23, and FIG. 24B is a cross-sectional view of therelevant part illustrating the orientation states of the liquid crystalmolecules in a state when there is a potential difference between thepixel electrodes and the drive electrodes in the configuration accordingto the comparative example illustrated in FIG. 23.

DETAILED DESCRIPTION

In the following, some embodiments of the technology will be describedin detail with reference to the accompanying drawings.

First Embodiment

(Exemplary Overall Configuration)

FIG. 1 illustrates an exemplary cross-sectional configuration of arelevant part of a display device according to a first embodiment of thetechnology. FIG. 2 illustrates an exemplary configuration of a drivecircuit of the display device according to the first embodiment.Referring to FIG. 1, the display device is provided with a pixelsubstrate 2, an opposed substrate 3 disposed to face the pixel substrate2, and a liquid crystal layer 6 inserted between the pixel substrate 2and the opposed substrate 3. The display device is further provided witha drive electrode driver 43, a gate driver 45, and a source driver 46 asillustrated in FIG. 2.

The pixel substrate 2 includes a TFT (Thin-Film Transistor) substrate 21serving as a circuit board, and a plurality of pixel electrodes 22disposed in matrix in a first direction (a horizontal direction) and asecond direction (a perpendicular direction) on the TFT substrate 21.Although not illustrated, the TFT substrate 21 is formed with TFTs forrespective pixels, and wirings such as source lines (image signalwirings) for supplying an image signal to the respective pixelelectrodes 22, gate lines for driving the respective TFTs, and drivesignal wirings for supplying a drive signal to the later-described driveelectrodes 33.

The opposed substrate 3 includes a glass substrate 31, a color filter 32formed on a first surface of the glass substrate 31, and the driveelectrodes (common electrodes) 33 formed on the color filter 32. Asecond surface of the glass substrate 31 is provided with a polarizingplate 35. The color filter 32 has a configuration in which, for example,color filter layers of three colors of red (R), green (G), and blue (B)are periodically aligned. Here, a set of three colors of R, G and B isassigned to each display pixel, although the number of colors and thetypes of colors are not limited thereto. The drive electrode 33 iscoupled to the TFT substrate 21 by a contact conductive pillar 7. Adrive signal Vcom which may have an AC rectangular waveform is appliedfrom the TFT substrate 21 through the contact conductive pillar 7 to thedrive electrode 33. The drive signal Vcom, together with a pixel voltageapplied to the pixel electrodes 22, defines a display voltage of each ofthe pixels, and may also be referred to as a common drive signal.

The source driver 46 supplies the image signal to each of the pixelelectrodes 22 through unillustrated the source lines. The gate driver 45applies a scan signal to the pixel electrodes 22, one pixel line (onehorizontal pixel line) in the first direction at a time through theunillustrated gate lines. The drive electrode driver 43 applies thedrive signal Vcom to the drive electrodes 33, in synchronization with atiming of application of the scan signal by the gate driver 45. Arelationship between the timing of application of the scan signal by thegate driver 45 and a timing of application of the drive signal Vcom bythe drive electrode driver 43 will be described later in detail.

The liquid crystal layer 6 modulates light passing therethrough inresponse to a state of an electric field. The liquid crystal layer 6 isa liquid crystal layer of a vertical alignment (VA) mode. FIGS. 7A and7B illustrate a configuration of the liquid crystal layer 6 of the VAmode, in which FIG. 7A illustrates orientation states of liquid crystalmolecules 61 in a state when there is no potential difference betweenthe pixel electrodes 22 and the drive electrodes 33, which correspondsto a state of black displaying. FIG. 7B illustrates the orientationstates of the liquid crystal molecules 61 in a state when there is apotential difference between the pixel electrodes 22 and the driveelectrodes 33, which corresponds to a state of white displaying or anintermediate state (halftone displaying). FIG. 8 illustrates a state ofan electric field (lines of electric force) E in the state in FIG. 7Bwhere the voltage is applied.

It is to be noted that FIGS. 7A and 7B illustrate an example of a VAmode of a two-domain orientation. The two-domain orientation VA mode hasa configuration in which one pixel (a single pixel) or one sub-pixel (asingle sub-pixel) is divided into two regions, and so operates that theorientation states of the liquid crystal molecules 61 differ from eachother between the two regions as illustrated in FIGS. 7B and 8.

Alignment films are respectively disposed between the liquid crystallayer 6 and the pixel substrate 2 and between the liquid crystal layer 6and the opposed substrate 3, and a light-incident side polarizing plateis disposed below the pixel substrate 2, illustrations of which areomitted in the drawings.

FIG. 6 is a perspective view illustrating an exemplary configuration ofthe drive electrodes 33 in the opposed substrate 3. Each of the driveelectrodes 33 is a strip-like electrode that extends in the firstdirection (the horizontal direction), and is arranged in a side-by-sidefashion in the second direction (the perpendicular direction). Each ofthe drive electrodes 33 is sequentially supplied with the drive signalVcom by the drive electrode driver 43, and is thus driven based onsequential scanning performed in a time-divisional fashion.

(Detailed Exemplary Configuration of Drive Electrode 33)

FIGS. 3 and 5 each illustrate a detailed exemplary configuration of theplurality of drive electrodes 33. Note that FIG. 5 is equivalent toillustration in which FIG. 3 is partially enlarged, although a ratio inFIG. 5 of a length in the horizontal direction and a length in theperpendicular direction is changed as compared with that of FIG. 3 forthe purpose of easier understanding of an electrode configuration. Also,in FIG. 5, a size of the pixel electrode 22 is equivalent to a size of asingle pixel or a single sub-pixel. A width W1 of the single driveelectrode 33 has a size corresponding to two or more pixel electrodes 22(four pixel electrodes 22 in FIG. 5) in the second direction (theperpendicular direction). Each of the drive electrodes 33 has aninner-electrode slit 33A so provided as to extend continuously in thefirst direction (the horizontal direction). An inter-electrode slit 33Bthat corresponds to the inner-electrode slit 33A is formed between theadjacent two drive electrodes 33. Each of the drive electrodes 33 has alength which is larger than that of an effective display region in thefirst direction. The inner-electrode slit 33A is provided at leastwithin the effective display region as illustrated in FIG. 3.

Each of the drive electrodes 33 is connected to the drive signal wiringformed on the TFT substrate 21 through the contact conductive pillar 7.FIG. 4 illustrates an exemplified connection structure utilizing thecontact conductive pillar 7 (a contact portion). The contact conductivepillar 7 is provided outside of the effective display region. Part (A)of FIG. 4 illustrates an example where the contact conductive pillars 7are provided at positions that are further outside of theinner-electrode slits 33A provided in the effective display region andthat are on both sides of the respective drive electrodes 33. Asillustrated in part (B) of FIG. 4, the contact conductive pillar 7 has apillar portion 7A, and a conductive film 7B that covers the pillarportion 7A. Alternatively, a configuration may be employed where theconduction is accomplished by using an anisotropic conductive film(ACF), instead of the configuration utilizing the contact conductivepillar 7 illustrated in part (B) of FIG. 4. The anisotropic conductivefilm is a film that may be obtained by mixing a thermosetting resin withfine metallic particles and forming a thus-obtained resultant into afilm. When the anisotropic conductive film is sandwiched between twocomponent parts and is pressurized while applying a heat, the metallicparticles dispersed in the film contact one another and thus form aconductive path. The metallic particles may be mixed in a given amountin a sealant used to adhere two glass substrates, to thereby allowconduction to be established only in a vertical direction withoutestablishing the conduction in a lateral direction. This method isextremely efficient in that the conduction can be established in thevertical direction without increasing the number of process steps.

Each of the drive electrodes 33 has one or more inner-electrode slits33A. FIGS. 3 and 5 each illustrate an example where each of the driveelectrodes 33 includes three inner-electrode slits 33A, although it isnot limited thereto. A spacing in the second direction between theadjacent inner-electrode slits 33A (when the drive electrode 33 has twoor more inner-electrode slits 33A), and a spacing in the seconddirection between the inner-electrode slit 33A and the inter-electrodeslit 33B that are adjacent to each other, are each set to have a sizecorresponding to the single pixel electrode 22. Also, as illustrated inFIG. 5, the inner-electrode slit 33A and the inter-electrode slit 33Bare each so configured as to be located in the center of the pixelelectrodes 22, for the plurality of drive electrodes 33. In other words,the inner-electrode slit 33A or the inter-electrode slit 33B is locatedin the center of each of the pixel electrodes 22, for each one pixelline (each one horizontal pixel line) in the first direction. Namely,each of the inner-electrode slit 33A and the inter-electrode slit 33Bextends to pass through center regions of the pixel electrodes 22 whichbelong to a pixel line in the first direction.

Referring now to FIGS. 9 and 10, a specific design example of the driveelectrode 33 will be described. FIG. 9 illustrates a human luminosityfactor (a spatial frequency characteristic). When a size such as a widthof the inner-electrode slit 33A and the inter-electrode slit 33B isincreased excessively, orientation states of liquid crystal moleculesare varied greatly between a portion which is between the pixels and acentral portion of the pixel due to an influence of a lateral electricfield to cause a defect. When this becomes prominent, a leakage of lightoccurs from a portion having the defect at the time of black displaying,reducing a contrast significantly. A width W2 of the inner-electrodeslit 33A and a width W3 of the inter-electrode slit 33B each may be setbased on a typical width between pixels such as about 10 micrometers orless, for example, although it is preferable that they be each smallerthan the width between the pixels in one embodiment. Further, in oneembodiment, the following design example is preferable with respect toeach element when taking the human luminosity factor into consideration,where a slit spacing (a slit pitch) W4 is a spacing between theinner-electrode slit 33A and the inter-electrode slit 33B that areadjacent to each other.

Width W1 of drive electrode 33: about 2 mm to 10 mm (preferably 3 mm to7 mm)

Width W2 of the inner-electrode slit 33A: 10 micrometers or less(preferably 3 mm to 6 mm)

Width W3 of the inter-electrode slit 33B: 10 micrometers or less(preferably 3 mm to 6 mm)

Slit spacing (slit pitch) W4: 500 micrometers or less (integral multipleof pixel pitch)

FIG. 12 describes a result of measurement on recognition of thestreak-like (slit-like) display defect when the slit pitch of the driveelectrode 33 was varied in the display device according to the firstembodiment. FIG. 11 describes a measurement environment thereof. Themeasurement was performed as illustrated in FIG. 11 for a typical visualenvironment of the display device, with a surface luminance of 300 cd/m²and a distance of about 20 centimeters away from the display device, forexample. Referring to FIG. 12, the streak-like display defect wasobserved when the slit pitch W4 was 600 micrometers or more. The displaydefect was hardly observed in a streak-like fashion when the slit pitchW4 was 500 and 400 micrometers, but was observed in the distance of 20centimeters or less. No streak-like display defect was observed at allwhen the slit pitch W4 was 300 micrometers or less.

Therefore, it is preferable that the slit pitch W4 be 500 micrometers orless, and more preferably be 300 micrometers or less.

(Exemplary Operation of Drive Control)

In the display device according to the first embodiment, the sourcedriver 46 illustrated in FIG. 2 supplies each of the pixel electrodes 22with the image signal. The gate driver 45 supplies each of the pixelelectrodes 22 with the scan signal (gate signal) used for selecting ahorizontal pixel line subjected to displaying. The drive electrodedriver 43 applies the drive signal Vcom to each of the drive electrodes33. The displaying of an image is performed by a combination of thosesignals.

Each of the drive electrodes 33 corresponds to a plurality of horizontalpixel lines in the display device according to the first embodiment.Thus, the single drive electrode 33 drives collectively the plurality ofhorizontal pixel lines. On the other hand, the gate driver 45 appliesthe scan signal, one horizontal pixel line at a time. Hence, adisplaying operation performed on a one horizontal pixel line basis iscarried out for the displaying operation according to the firstembodiment.

As one example, description will be given on signal-application timingsof the drive signal Vcom and the scan signal when the drive electrodes33 and the pixel electrodes 22 have a configuration illustrated in FIG.13. FIG. 13 illustrates the example where the five inner-electrode slits33A are provided in the single drive electrode 33. Also, theinter-electrode slit 33B is formed between the N-th drive electrode 33and the (N+1) th drive electrode 33. The horizontal pixel linescorresponding to the first to the fifth inner-electrode slits 33A fromthe top in the N-th drive electrode 33 are defined as n-th to (n+4) thhorizontal pixel lines, respectively. Further, the horizontal pixel linecorresponding to the inter-electrode slit 33B between the N-th driveelectrode 33 and the (N+1) th drive electrode 33 is defined as (n+5) thhorizontal pixel line. The gate drive 45 sequentially applies the scansignal in an order of n-th horizontal pixel line, (n+1) th horizontalpixel line, (n+2) th horizontal pixel line, and so on.

Referring to FIGS. 14, (A) and (B) illustrate examples of timings of thedrive signals Vcom applied to the N-th drive electrode 33 and the (N+1)th drive electrode 33 illustrated in FIG. 13, respectively. In FIG. 14,(C) to (E) illustrate examples of timings of the scan signals applied tothe n-th horizontal pixel line, the (n+1) th horizontal pixel line, andthe (n+5) th horizontal pixel line, respectively.

In the display device according to the first embodiment, when the scansignal is to be applied to a pixel line in a region which does notcorrespond to the inter-electrode slit 33B (i.e., when the scan signalis to be applied to the pixel line corresponding to the inner-electrodeslit 33A), the drive signal Vcom may be applied only to the single driveelectrode 33 that corresponds to a pixel line to which the scan signalis to be applied. In the illustrated example of FIG. 13, the drivesignal Vcom is only applied to the N-th drive electrode 33 when the scansignal is to be applied to the n-th horizontal pixel line to the (n+4)th horizontal pixel line as illustrated in (A), (C), and (D) of FIG. 14.On the other hand, when the scan signal is to be applied to the pixelline located in the region corresponding to the inter-electrode slit33B, the drive signals Vcom are applied (for example, simultaneously) toboth of the two (a couple of the) drive electrodes 33 that are adjacentto that inter-electrode slit 33B. In the illustrated example of FIG. 13,the drive signals Vcom are applied (for example, simultaneously) to bothof the N-th drive electrode 33 and the (N+1) th drive electrode 33 whenthe scan signal is to be applied to the (n+5) th horizontal pixel lineas illustrated in (A), (B), and (E) of FIG. 14.

(Effect)

According to the display device as described in the foregoing, each ofthe drive electrodes 33 has the one or more inner-electrode slits 33Aextending in the first direction at least within the effective displayregion, and the inter-electrode slit 33B corresponding to theinner-electrode slit 33A is formed between the two adjacent driveelectrodes 33. This makes it possible to reduce a structural differencebetween a portion where the drive electrode 33 is formed and a portionbetween the two adjacent drive electrodes 33. Thus, it is possible touniformize the states of orientation of the liquid crystal molecules 61throughout the entire display region when the display device is appliedto a liquid crystal display of the VA mode. Hence, it is possible tosuppress deterioration in display quality in the VA mode liquid crystaldisplay. Also, each of the inner-electrode slit 33A and theinter-electrode slit 33B extends to pass through the center regions ofthe pixel electrodes 22. Hence, it is possible to perform an efficientorientation control suitable for the VA mode liquid crystal display, ascompared with an example where a slit is disposed between the adjacentpixel electrodes 22.

A reference is now made to a configuration according to a comparativeexample illustrated in FIGS. 23 to 24B. As illustrated in FIG. 23, thecomparative example has a configuration in which the inner-electrodeslit 33A and the inter-electrode slit 33B are each located between theadjacent two pixel electrodes 22. FIGS. 24A and 24B illustrateorientation states of the liquid crystal molecules 61, when the liquidcrystal layer 6 is driven based on the two-domain orientation VA modeand when the electrode configuration illustrated in FIG. 23 is employed.FIG. 24A illustrates the orientation states of the liquid crystalmolecules 61 in a state when there is no potential difference betweenthe pixel electrodes 22 and the drive electrodes 33, which correspondsto a state of black displaying. FIG. 24B illustrates the orientationstates of the liquid crystal molecules 61 in a state when there is apotential difference between the pixel electrodes 22 and the driveelectrodes 33, which corresponds to a state of white displaying or anintermediate state (halftone displaying). FIG. 24B also illustrates astate of an electric field (lines of electric force) E in the statewhere the voltage is applied. The configuration illustrated in FIG. 23establishes a structure where a position of a slit of the pixelelectrode 22 and that of the drive electrode 33 are symmetric verticallywith respect to each other as illustrated in FIGS. 24A and 24B. Thus,orientations of the liquid crystal molecules 61 are not defined at thetime of the voltage application as illustrated in FIG. 24B, causingdisadvantages such as an orientation defect and decrease in responsespeed. In contrast, the first embodiment has the configuration in whichthe inner-electrode slit 33A and the inter-electrode slit 33B are eachlocated in the center of the pixel electrodes 22, i.e., each of theinner-electrode slit 33A and the inter-electrode slit 33B extends topass through the center regions of the pixel electrodes 22. Hence, thefirst embodiment makes it possible to prevent the disadvantages such asthe orientation defect, and to efficiently operate or orient the liquidcrystal molecules 61.

Second Embodiment

Hereinafter, a display device according to a second embodiment of thetechnology will be described. Note that the same or equivalent elementsas those of the display device according to the first embodimentdescribed above are denoted with the same reference numerals, and willnot be described in detail.

FIG. 15 illustrates a configuration of the drive electrodes 33 in thedisplay device according to the second embodiment. The second embodimenthas a configuration in which the inner-electrode slit 33A is notprovided, and the inter-electrode slits 33B are each located in thecenter of the pixel electrodes 22 for each one pixel line in the firstdirection (the horizontal direction), i.e., the inter-electrode slit 33Bextends to pass through a center region of each of the pixel electrodes22. A width in the second direction (the perpendicular direction) ofeach of the drive electrodes 33 has a size corresponding to a width inthe second direction of the single pixel electrode 22.

As one example, description will be given on the signal-applicationtimings of the drive signal Vcom and the scan signal when the driveelectrodes 33 and the pixel electrodes 22 have the configurationillustrated in FIG. 15. In the illustrated example of FIG. 15, thehorizontal pixel line corresponding to the inter-electrode slit 33Bbetween the N-th drive electrode 33 and the (N+1) th drive electrode 33is defined as n-th horizontal pixel line, and the subsequent horizontalpixel line corresponding to the inter-electrode slit 33B between the(N+1) th drive electrode 33 and the (N+2) th drive electrode 33 isdefined as (n+1) th horizontal pixel line. The gate driver 45sequentially applies the scan signal in an order of n-th horizontalpixel line, (n+1) th horizontal pixel line, (n+2) th horizontal pixelline, and so on.

Referring to FIGS. 16, (A), (B), and (C) illustrate the examples oftimings of the drive signals Vcom applied to the N-th drive electrode33, the (N+1) th drive electrode 33, and the (N+2) th drive electrode 33illustrated in FIG. 15, respectively. In FIGS. 16, (D) and (E)illustrate the examples of timings of the scan signals applied to then-th horizontal pixel line and the (n+1) th horizontal pixel line,respectively.

In the display device according to the second embodiment, when the scansignal is to be applied from the gate driver 45 to a pixel line locatedin a region corresponding to the single inter-electrode slit 33B, thedrive electrode driver 43 illustrated in FIG. 2 applies the drivesignals Vcom (for example, simultaneously) to both of the two (a coupleof the) drive electrodes 33 that are adjacent to that singleinter-electrode slit 33B. In the illustrated example of FIG. 15, thedrive signals Vcom are applied (for example, simultaneously) to both ofthe N-th drive electrode 33 and the (N+1) th drive electrode 33 when thescan signal is to be applied to the n-th horizontal pixel line, asillustrated in (A), (B), and (D) of FIG. 16. Likewise, the drive signalsVcom are applied (for example, simultaneously) to both of the (N+1) thdrive electrode 33 and the (N+2) th drive electrode 33 when the scansignal is to be applied to the (n+1) th horizontal pixel line, asillustrated in (B), (C), and (E) of FIG. 16.

Third Embodiment

Hereinafter, a display device according to a third embodiment of thetechnology will be described. Note that the same or equivalent elementsas those of the display device according to the first embodiment or thesecond embodiment described above are denoted with the same referencenumerals, and will not be described in detail.

The display device according to the third embodiment differs partiallyfrom the configuration of the drive electrodes 33 illustrated in FIG. 5of the display device according to the first embodiment described above,in terms of a configuration (a slit shape) of the inner-electrode slit33A. FIG. 17 illustrates a configuration of the drive electrodes 33according to the third embodiment. In the above-described firstembodiment, the inner-electrode slits 33A are provided continuously toextend in the first direction (the horizontal direction). In contrast,in this embodiment, the inner-electrode slits 33A are not continuous inthe first direction, and discontinuous regions 33C are partially formedto provide slits in an intermittent fashion as illustrated in FIG. 17.The discontinuous region 33C is formed at a position between the pixelelectrodes 22 in the first direction, i.e., each of the inner-electrodeslits 33A is configured to be discontinuous in a region between thepixel electrodes 22 in the first direction. The provision of thediscontinuous region 33C makes it possible to lower a resistance of thedrive electrode 33 than the case where the continuous inner-electrodeslit 33A is provided.

Fourth Embodiment

Hereinafter, a display device according to a fourth embodiment of thetechnology will be described. Note that the same or equivalent elementsas those of the display devices according to the first to the thirdembodiments described above are denoted with the same referencenumerals, and will not be described in detail.

The first embodiment described above employs the two-domain orientationVA mode, whereas the fourth embodiment employs a VA mode of afour-domain orientation. The four-domain orientation VA mode has aconfiguration in which a single pixel or a single sub-pixel is dividedinto four regions, and so operates that the orientation states of theliquid crystal molecules 61 differ from one another among the fourregions.

FIG. 18 schematically illustrates a configuration of the pixelelectrodes 22 and a configuration of the drive electrodes 33 accordingto the fourth embodiment. FIG. 19 illustrates a detailed configurationthereof, and FIG. 20 illustrates a part of the configuration illustratedin FIG. 19 in an enlarged fashion. FIGS. 19 and 20 illustrate only aconfiguration of a slit portion (the inner-electrode slit 33A and theinter-electrode slit 33B) for the configuration of the drive electrodes33. Also, the configuration is illustrated in FIGS. 19 and 20 where eachof the pixel electrodes 22 is provided in a sub-pixel unit.

In the fourth embodiment, the inner-electrode slit 33A is provided notonly in the first direction (the horizontal direction) but also in thesecond direction (the perpendicular direction) in a central part of thepixel electrode 22 as illustrated in FIGS. 18 to 20. Thus, theinner-electrode slit 33A is in a cross-like shape in the central part ofthe single pixel electrode 22 (the sub-pixel). The configurationaccording to the fourth embodiment described above makes it possible toefficiently operate or orient the liquid crystal molecules 61 in fourdomains.

Fifth Embodiment

Hereinafter, a display device according to a fifth embodiment of thetechnology will be described. Note that the same or equivalent elementsas those of the display devices according to the first to the fourthembodiments described above are denoted with the same referencenumerals, and will not be described in detail.

The fifth embodiment employs the four-domain orientation VA mode as inthe fourth embodiment described above.

FIG. 21 illustrates a configuration of the pixel electrodes 22 and aconfiguration of the drive electrodes 33 according to the fifthembodiment. FIG. 21 illustrates a detailed configuration thereof, andFIG. 22 illustrates a part of the configuration illustrated in FIG. 21in an enlarged fashion. FIGS. 21 and 22 illustrate only a configurationof a slit portion (the inner-electrode slit 33A and the inter-electrodeslit 33B) for the configuration of the drive electrodes 33. Also, theconfiguration is illustrated in FIGS. 21 and 22 where each of the pixelelectrodes 22 is provided in a sub-pixel unit.

In the fifth embodiment, the inner-electrode slit 33A is provided notonly in the first direction (the horizontal direction) but also in thesecond direction (the perpendicular direction) in the central part ofthe pixel electrode 22, as in the fourth embodiment described above withreference to FIGS. 19 and 20. Thus, the inner-electrode slit 33A is inthe cross-like shape in the central part of the single pixel electrode22 (the sub-pixel). The configuration according to the fifth embodimentdescribed above makes it possible to efficiently operate or orient theliquid crystal molecules 61 in four domains.

Further, in the fifth embodiment, fine pixel electrode slits 22B areprovided in the pixel electrode 22 as illustrated in FIG. 22. Theprovision of the fine pixel electrode slits 22B makes it possible toperform an orientation control of the liquid crystal molecules 61 indesired orientations more accurately.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-187176 filed in theJapan Patent Office on Aug. 24, 2010, the entire content of which ishereby incorporated by reference.

Although the technology has been described in terms of exemplaryembodiments, it is not limited thereto. It should be appreciated thatvariations may be made in the described embodiments by persons skilledin the art without departing from the scope of the technology as definedby the following claims. The limitations in the claims are to beinterpreted broadly based on the language employed in the claims and notlimited to examples described in this specification or during theprosecution of the application, and the examples are to be construed asnon-exclusive. For example, in this disclosure, the term “preferably”,“preferred” or the like is non-exclusive and means “preferably”, but notlimited to. The use of the terms first, second, etc. do not denote anyorder or importance, but rather the terms first, second, etc. are usedto distinguish one element from another. Moreover, no element orcomponent in this disclosure is intended to be dedicated to the publicregardless of whether the element or component is explicitly recited inthe following claims.

What is claimed is:
 1. A display device, comprising: common electrodesincluding adjacent common electrodes with an inter-electrode slitbetween the adjacent common electrodes, each common electrode having aninner-electrode slit; and pixel electrodes including a first pluralityof first pixel electrodes, a second plurality of first pixel electrodes,and a plurality of second pixel electrodes between the first pluralityof first pixel electrodes and the second plurality of first pixelelectrodes, wherein, each inner-electrode slit and the inter-electrodeslit have a length in a first direction, respectively, the pixelelectrodes are arrayed at least along the first direction, each of thecommon electrodes overlies a respective plurality of the first pixelelectrodes, the inner-electrode slit of each common electrode overlies acenter region of at least one of the respective plurality of first pixelelectrodes, and the inter-electrode slit overlies a center region ofeach of the plurality of second pixel electrodes.
 2. The display deviceaccording to claim 1, wherein, each inner-electrode slit overlies thecenter region of each of the respective plurality of first pixelelectrodes.
 3. The display device according to claim 1, wherein: each ofthe common electrodes has more than one inner-electrode slit including afirst inner-electrode slit and a second inner-electrode slit, therespective plurality of first pixel electrodes are arrayed in the firstdirection and a second direction that crosses the first direction, andthe first inner-electrode slit and the second inner electrode slitoverlie center regions of different first pixel electrodes of therespective plurality of first pixel electrodes.
 4. The display deviceaccording to claim 1, wherein each of the inner-electrode slits isdiscontinuous in a region between two adjacent first pixel electrodes.5. The display device according to claim 1, wherein each inner-electrodeslit has a first portion with a length extending in the first directionand in a second portion with a length extending in a second directioncrossing the first direction.
 6. The display device according to claim1, wherein the inter-electrode slit has a first portion with a lengthextending in the first direction and a second portion with a lengthextending in a second direction crossing the first direction.
 7. Thedisplay device according to claim 1, wherein: each of theinter-electrode slit and the inner-electrode slit extends in the firstdirection, and at least one of the pixel electrodes has one or moreslits extending in a third direction different from either the firstdirection or a second direction crossing the first direction.
 8. Thedisplay device according to claim 1, wherein: each of the commonelectrodes has a length in the first direction and a width in a seconddirection which crosses the first direction, corresponding to a size inthe second direction of each of the pixel electrodes, and eachinner-electrode slit overlies the center region of each of therespective plurality of first pixel electrodes arrayed in the firstdirection.
 9. The display device according to claim 1, wherein, when animage signal is applied to a pixel line located in a regioncorresponding to the inter-electrode slit, a drive signal is applied toboth of the adjacent common electrodes.
 10. The display device accordingto claim 1, further comprising: a pixel substrate having the pixelelectrodes arranged in an effective display region, image signal wiring,and drive signal wiring, the image signal wiring being coupled to atleast one of the pixel electrodes; an opposed substrate facing the pixelsubstrate and having the common electrodes; and a contact portion at alocation which is between the pixel substrate and the opposed substrateand outside the effective display region, the contact portion allowingeach common electrode to be in conduction with the drive signal wiring.11. The display device according to claim 1, wherein, a first spacing,which is a distance between each inner-electrode slit andinter-electrode slit that are adjacent to each other, is about 500micrometers or less.
 12. The display device according to claim 1,wherein: each of the common electrodes has two or more inner-electrodeslits, and a second spacing, which is a distance between adjacentinner-electrode slits, is about 500 micrometers or less.
 13. The displaydevice according to claim 11, wherein the first spacing is about 300micrometers or less.
 14. The display device according to claim 12,wherein the second spacing is about 300 micrometers or less.
 15. Thedisplay device according to claim 1, further comprising a liquid crystallayer of a vertical alignment mode disposed between the commonelectrodes and the pixel electrodes.
 16. The display device according toclaim 1, wherein, when an image signal is applied to one of the secondpixel electrodes, a drive signal is applied to both of the adjacentcommon electrodes.
 17. The display device according to claim 10, whereinthe contact portion is a contact conductive pillar.
 18. The displaydevice according to claim 10, wherein the contact portion is ananisotropic conductive film.
 19. The display device according to claim1, wherein each of the common electrodes has a width in a seconddirection, which crosses the first direction, that is larger than awidth in the second direction of each of the pixel electrodes.
 20. Adisplay device, comprising: a plurality of common electrodes including afirst common electrode and a second common electrode adjacent to thefirst common electrode, each of the first common electrode and thesecond common electrode having a length extending in a first directionand each having an inner-electrode slit; an inter-electrode slit betweenthe first common electrode and the second common electrode; and aplurality of pixel electrodes including a first pixel electrode and asecond pixel electrode adjacent to the first pixel electrode in thefirst direction and a third pixel electrode adjacent to the first pixelelectrode in a second direction crossing the first direction, wherein,the inner-electrode slit of the first common electrode overlies centerregions of the first pixel electrode and the second pixel electrode, theinter-electrode slit overlies a center region of the third pixelelectrode, the third pixel electrode is overlapped by both the firstcommon electrode and the second common electrode, and the first pixelelectrode and the second pixel electrode are not overlapped by thesecond common electrode.